Scientists from Shirshov Institute of Oceanology of the Russian Academy of Sciences have the following data on Russia’s coastline – 60 thousand km long and 5 million square km of shelf, which is about one third of Russia’s territory. About 17 million people dwell on the shores of Russian seas – about 12 per cent of the population. Scientific research has revealed striking results – all Russian seas are contaminated with pesticides – chlororganic compounds for fighting pests: pollutants, considered to be most hazardous for human health. However, the results were predictable since up to 3.2 million tons of herbicides and fungicides were used in the world in the end of 80s of the last century – an average of 0.6 kilograms per each Earth dweller. The USSR accounted for 12 per cent of pesticide world production at that time.

The scientists have analyzed the samples of water and bottom sediments, which were contaminated with pesticides - contamination level is moderate, not exceeding maximum permissible concentrations of 0.01 microgram per liter. Most polluted areas are sea shelf territories and estuary parts. The highest pesticide (mostly dichloro-diphenyl-trichloroethane family) concentration was detected in bottom sediments. The most polluted sea is the Sea of Japan – the Ussurian Bay, where concentration of DDT and its metabolites reached 0.2-9.2 microgram per liter with maximum reaching 323 microgram per liter, i.e. much higher than maximum permissible concentrations.

Shelf territories of internal seas (The Black Sea, the Azov Sea, the Caspian Sea and the Baltic Sea) showed background concentrations of chlororganic compounds. Prevailing pesticides were the following – DDT, DDD (dichlorodiphenyldichloroethan), DDE (dichlorodiphenylethylene) and chlorophos. The most polluted site of the Baltic Sea is the Nevskaya Guba bay, where DDT and DDE water concentrations reached 30-70 and 10-20 nanograms per liter respectively exceeding maximum permissible concentrations sevenfold. Scientists still hope that if pesticide usage is restricted (it was limited in the beginning of the nineties due to economical reasons), seawater self-purification occurs once in 10-15 years.

Oceanologists have the information that Russian seas hide 23 dumps of chemical and explosive wastes. The rating of Russian seas according to their contamination level is the following (in descending order): the Azov Sea – the North and the Middle Caspian – the Sea of Japan – the Baltic Sea – the Barents Sea – the Pechora Sea – the Black Sea – the Okhotskoe Sea – the Karskoe Sea – the Laptev Sea – the East Siberian Sea – the Chukchee Sea. Open waters of said seas are less contaminated that coastal ones. Some areas – bays, ports and gulfs - have catastrophic levels of contamination. Most dangerous poisonous chemicals (PC), which are drowned in the Baltic Sea (in 1945 one third of Germany’s poisonous chemicals was buried there) – prussic acid (hydrocyanic acid) and poison gases (mustard, adamsite and others).

Scientists tend to think that the main potential hazard of drowned chemical weapons is in toxicity of its components, bioaccumulation effect (accumulation with poisonous substances in bottom dwellers) and long-term contamination of bottom sediments with arsenic of lewisite. Some shallow waters of the Baltic Sea are dangerous for possible transmission of toxic agents via food chain to fish, birds and human beings. When consuming fish products with high arsenic content, risks of having a tumor grow thousand-fold. Oceanologists think that chemical weapons will become really dangerous, when lifted by nets of fishing ships therefore clear soil dumping is required.

Scientists remind us that changes in seawater composition were the reason for appearing and spreading of new diseases – urbanites, represented by toxicological, endocrine, allergic and genetic diseases.

Source:
    http://www.inauka.ru/

Kizilova Anna